Glass fiber composite of improved processability

ABSTRACT

Fiber reinforced composition comprising a heterophasic propylene copolymer, a propylene homopolymer and/or a propylene copolymer, and fibers, wherein the propylene copolymer comprises not more than 2.0 wt.-% C2 to C10 α-olefins other than propylene, the propylene homopolymer and the propylene copolymer have a melt flow rate MFR 2  (230° C.) of at least 500 g/10 min, and the composition has a melt flow rate MFR 2  (230° C.) of at least 10 g/10 min.

This application is a National Stage of International Application No.PCT/EP2010/064640, filed Oct. 1, 2010. This application claims priorityto European Patent Application No. 09172622.4 filed on Oct. 9, 2009. Thedisclosures of the above applications are incorporated herein byreference.

The present invention concerns an improved fiber reinforcedpolypropylene composition as well as articles formed there from.

Polypropylene is a material used in a wide variety of technical fieldsand reinforced polypropylenes have in particular gained relevance infields previously exclusively relying on non-polymeric materials, inparticular metals. One particular example of reinforced polypropylenesare glass fiber reinforced polypropylenes. Such materials enable atailoring of the properties of the composition by selecting the type ofpolypropylene, the amount of glass fiber and sometimes by selecting thetype of coupling agent used. Accordingly, nowadays the glass-fiberreinforced polypropylene is a well established material for applicationsrequiring high stiffness, heat deflection resistance and resistance toboth impact and dynamic fracture loading (examples include automotivecomponents with a load-bearing function in the engine compartment,support parts for polymer body panels, washing machine and dishwashercomponents). However one drawback of the commercial available fiberreinforced material is its limited flowability and processability. Thefact that there is a clear negative correlation between glass fibercontent (usually ranging between 10 and 40 wt.-%) and flowability (MFR)makes the forming of thin-wall or otherwise delicate parts difficult orimpossible.

Thus so far it has been impossible to increase the flowability byvarying the polymer material without sacrificing mechanical performance,especially impact strength.

EP 1 357 144 B1 describes the combination of either a propylenehomopolymer with an heterophasic propylene copolymer or two differentheterophasic propylene copolymers as matrix for glass fiber reinforcedmaterial (5-50 wt % fiber content). Polymer component A (a propylenehomopolymer or copolymer) has an melt flow rate (MFR₂) above 10 g/10min, while polymer component B (a heterophasic copolymer) has a meltflow rate (MFR₂) of 0.1 to 2.0 g/10 min. The overall melt flow rate(MFR₂) of the examples is 1.3 to 6.5 g/10 min, with significantly worsemechanics at higher melt flow rates.

EP 0 206 034 A1 describes polyolefin compositions comprising a fibrousinorganic filler (3 to 25 wt.-%). The matrix for the fibrous filler is acombination of a propylene homopolymer or copolymer and a polyethylenehaving a melt flow rate (MFR₂) of more than 10 g/10 min with said meltflow rate (MFR₂) being 0.1 to 50 times the melt flow rate (MFR₂) of thepolypropylene component. The overall flowability in terms of melt flowrate (MFR₂) of the examples can be estimated from the components to bebetween 1 and 4 g/10 min.

U.S. Pat. No. 5,382,459 covers glass fiber reinforced polypropylenecompositions consisting essentially of a heterophasic copolymer, acarboxylic acid modified polypropylene (as compatibilizer) and glassfiber. The target applications are injection molded wheel caps of highgloss and strength. Neither the overall melt flow rate (MFR₂) nortoughness are quantified.

WO 2008/074715 A1 refers to filled polyolefin compositions comprising 15to 55 wt.-% polypropylene (bimodal mixture with two components havingmelt flow rates (MFR₂) of more than 500 g/10 min and 0.1 to 30 g/10 min,respectively, optionally with 0.5 to 15 wt.-% compatibilizer), 4 to 25wt.-% elastomeric polymer and 20 to 80 wt.-% of filler. Examplescomprising glass fibers (50 wt.-%) have an overall melt flow rate (MFR₂)of 3.6 to 7.8 g/10 min with Charpy (IS 179 1eU, +23° C.) ranging from 61to 82 kJ/m² and tensile modulus from 9700 to 13100 MPa. However theflowability of the compositions still not satisfying.

Accordingly the object of the present is to provide a fiber reinforcedcomposition with excellent flowability without compromising themechanical properties, like flexural modulus, impact strength andelongation at break.

The finding of the present invention is that the fibrous reinforcingmaterial must be embedded in a polymer composition which comprises a lowviscous polypropylene and a heterophasic polypropylene, saidheterophasic polypropylene contains not more than 45 wt.-% of anelastomeric copolymer.

Therefore the present invention is directed to a fiber reinforcedcomposition (1^(st) embodiment) comprising

-   -   (a) a heterophasic propylene copolymer (HECO),    -   (b) a propylene homopolymer (H-PP1) and/or a propylene copolymer        (C-PP1),    -   (c) fibers (F),    -   (d) optionally an elastomer (E2),    -   and    -   (e) optionally a compatibilizer (C),    -   wherein    -   (i) the heterophasic propylene copolymer (HECO) comprises a        polypropylene matrix (M-PP) and dispersed therein an elastomeric        copolymer (E1) comprising units derived from        -   propylene and        -   ethylene and/or C4 to C20 α-olefin,    -   (ii) the xylene cold soluble content (XCS) measured according        ISO 6427 (23° C.) of the heterophasic propylene copolymer (HECO)        is not more than 45 wt.-%, preferably in the range of 5 to 45        wt.-%,    -   (iii) the propylene copolymer (C-PP1) comprises not more than        2.0 wt.-% C2 to C10 α-olefins other than propylene, and    -   (iv) the propylene homopolymer (H-PP1) and the propylene        copolymer (C-PP1) have a melt flow rate MFR₂ (230° C.) measured        according to ISO 1133 of at least 500 g/10 min.

Preferably the fiber reinforced composition according to the 1^(st)embodiment is further characterized in that the polypropylene matrix(M-PP) has a lower melt flow rate MFR₂ (230° C.) measured according toISO 1133 than the propylene homopolymer (H-PP1) and the propylenecopolymer (C-PP1). Further it is appreciated that the fiber reinforcedcomposition according to the 1^(st) embodiment has a melt flow rate MFR₂(230° C.) measured according to ISO 1133 of at least 10 g/10 min.

Alternatively the inventive composition (2^(nd) embodiment) can bedefined as a fiber reinforced composition comprising

-   -   (a) a heterophasic propylene copolymer (HECO)    -   (b) a propylene homopolymer (H-PP1) and/or a propylene copolymer        (C-PP1),    -   (c) fibers (F),    -   (d) optionally an elastomer (E2),    -   and    -   (e) optionally a compatibilizer (C),    -   wherein    -   (i) the propylene copolymer (C-PP1) comprises not more than 2.0        wt.-% C2 to C10 α-olefins other than propylene,    -   (ii) the propylene homopolymer (H-PP1) and the propylene        copolymer (C-PP1) have a melt flow rate MFR₂ (230° C.) measured        according to ISO 1133 of at least 500 g/10 min, and    -   (iii) the composition has a melt flow rate MFR₂ (230° C.)        measured according to ISO 1133 of at least 10 g/10 min.

Preferably the fiber reinforced composition according to the 2^(nd)embodiment is further characterized in that the heterophasic propylenecopolymer (HECO) comprises a polypropylene matrix (M-PP) and dispersedtherein an elastomeric copolymer (E1) comprising units derived from

-   -   propylene and    -   ethylene and/or C4 to C20 α-olefin.

More preferably the xylene cold soluble content (XCS) measured accordingISO 6427 (23° C.) of the heterophasic propylene copolymer (HECO) is notmore than 45 wt.-%, preferably in the range of 5 to 45 wt.-%.Additionally it is appreciated that the polypropylene matrix (M-PP) hasa lower melt flow rate MFR₂ (230° C.) measured according to ISO 1133than the propylene homopolymer (H-PP1) and the propylene copolymer(C-PP1).

It has been surprisingly found out that the fiber reinforced compositionpossesses very good flowabilty by keeping the other properties, likestiffness and impact, on the desired levels. In particular the flexuralmodulus, the Charpy impact, and the elongation at break fulfill therequirements set for instance by the automobile industry and theappliance industry (see tables 2 to 4).

The present invention according to the 1^(st) and 2^(nd) embodiment willbe now described in more detail together.

It is apparent from the wording used for the different polymers (HECO,M-PP, H-PP1, C-PP1, H-PP2, C-PP2, E1, E2 and C) according to the presentinvention that they must (chemically) differ from each other. Thepresent invention is further characterized by the fact that none of thepolymers HECO (and its individual components M-PP (H-PP2, C-PP2) andE1), H-PP1, C-PP1 and E2 employed is branched. In other words thepolymers HECO (and its individual components M-PP (H-PP2, C-PP2) andE1), H-PP1, C-PP1 and E2 have a branching index g′ of at least 0.90,more preferably of at least 0.95, like of 1.00. The branching index g′is defined as g′=[IV]_(br)/[IV]_(lin) in which g′ is the branchingindex, [IV]_(br) is the intrinsic viscosity of the branchedpolypropylene and [IV]_(lin) is the intrinsic viscosity of the linearpolypropylene having the same weight average molecular weight (within arange of ±10%) as the branched polypropylene. Thereby, a low g′-value isan indicator for a high branched polymer. In other words, if theg′-value decreases, the branching of the polypropylene increases.Reference is made in this context to B. H. Zimm and W. H. Stockmeyer, J.Chem. Phys. 17,1301 (1949). This document is herewith included byreference.

The expression “heterophasic” indicates that the elastomeric copolymer(E1) and—if present—also the elastomer (E2) is (are) preferably (finely)dispersed at least in the polypropylene matrix (M-PP) of theheterophasic propylene copolymer (HECO). In other words the elastomericcopolymer (E1) and the elastomer (E2) form inclusions in thepolypropylene matrix (M-PP). Thus the polypropylene matrix (M-PP)contains (finely) dispersed inclusions being not part of the matrix andsaid inclusions contain the elastomeric copolymer (E1) and the elastomer(E2), respectively. The term “inclusion” according to this inventionshall preferably indicate that the matrix and the inclusion formdifferent phases within the heterophasic propylene copolymer (HECO),said inclusions are for instance visible by high resolution microscopy,like electron microscopy or scanning force microscopy. The final fiberreinforced composition is probably of a complex structure. Probably thepolypropylene matrix (M-PP) together with the propylene homopolymer(H-PP1) and/or the propylene copolymer (C-PP1) form a continuous phasebeing the matrix of the fiber reinforced composition wherein theelastomeric copolymer (E1) and optionally the elastomer (E2) formtogether or individually inclusions dispersed therein.

Additionally the inclusions of the final fiber reinforced compositionmay also contain the fibers (F); however preferably the fibers (F) aredispersed individually as separate inclusions within the final matrix ofthe fiber reinforced composition.

Further the fiber reinforced composition according to the presentinvention preferably comprises

-   -   the heterophasic propylene copolymer (HECO),    -   the propylene homopolymer (H-PP1) and/or a propylene copolymer        (C-PP1),    -   optionally the elastomer (E2), and    -   optionally the compatibilizer (C),        as the only polymer components within the fiber reinforced        composition, i.e. no other polymer components are present.

Especially good results are achievable in case the fiber reinforcedcomposition according to this invention comprises

-   -   (a) 5.0 to 50.0 wt.-%, more preferably 7.0 to 45.0 wt.-%, still        more preferably 9.0 to 40 wt.-%, of the heterophasic propylene        copolymer (HECO),    -   (b) 10.0 to 60.0 wt.-%, more preferably 12.0 to 55.0 wt.-%,        still more preferably 15.0 to 50.0 wt.-%, of the propylene        homopolymer (H-PP1), of the propylene copolymer (C-PP1), or of        the mixture of the propylene homopolymer (H-PP1) and the        propylene copolymer (C-PP1),    -   (c) 10.0 to 45.0 wt.-%, more preferably 20.0 to 43.0 wt.-%,        still more preferably 30.0 to 40.0 wt.-%, of fibers,    -   (d) optionally 3.0 to 20.0 wt.-%, more preferably 5.0 to 16.0        wt.-%, still more preferably 6.0 to 13.0 wt-%, of the elastomer        (E2), and    -   (e) optionally 0.5 to 4.0 wt.-%, more preferably 1.0 to 3.5        wt.-%, still more preferably 1.5 to 2.5 wt.-%, of the        compatibilizer (C),        based on the total composition, preferably based on the polymers        present in the fiber reinforced composition.

Further it is desired that the fiber reinforced composition has a ratherhigh melt flow rate. The melt flow rate mainly depends on the averagemolecular weight. This is due to the fact that long molecules render thematerial a lower flow tendency than short molecules. An increase inmolecular weight means a decrease in the MFR-value. The melt flow rate(MFR) is measured in g/10 min of the polymer discharged through adefined die under specified temperature and pressure conditions and themeasure of viscosity of the polymer which, in turn, for each type ofpolymer is mainly influenced by its molecular weight but also by itsdegree of branching. The melt flow rate measured under a load of 2.16 kgat 230° C. (ISO 1133) is denoted as MFR₂ (230° C.). Accordingly, it ispreferred that in the present invention the fiber reinforced compositionhas an MFR₂ (230° C.) of at least 10 g/10 min, more preferably of atleast 12 g/10 min, still more preferably of at least 14 g/10 min. On theother hand the final melt flow rate MFR₂ (230° C.) should be not toohigh to avoid any separation tendencies of the fibers (F). Thus it isappreciated that the final melt flow rate MFR₂ (230° C.) of the fiberreinforced composition is in the range of 10 to 100 g/10 min, preferablyof 12 to 80 g/10 min, more preferably of 13 to 60 g/10 min.

Further it has been found out that especially good results areachievable in case the xylene cold soluble content (XCS) (measuredthroughout the present invention according ISO 6427 (23° C.)) of theheterophasic propylene copolymer (HECO) is neither too high nor too low,i.e. is in the range of 5 to 45 wt.-%.

Additionally it is appreciated that the melt flow rate MFR₂ (230° C.)(measured according to ISO 1133) of the heterophasic propylene copolymer(HECO) is rather high, i.e. is of more than 10 g/10 min, more preferablyof more than 20 g/10 min, still more preferably of more than 40 g/10min, still yet more preferably of more than 60 g/10 min, like of morethan 90 g/10 min. Thus it is preferred that the melt flow rate MFR₂(230° C.) (measured according to ISO 1133) of the heterophasic propylenecopolymer (HECO) is in the range of 10.0 to 300.0 g/10 min, morepreferably in the range of 30.0 to 200.0 g/10 min, still more preferablyin the range of 40 to 150 g/10 min.

As stated above the heterophasic propylene copolymer (HECO) haspreferably not only a rather high melt flow rate MFR₂ (230° C.) but alsoa rather low xylene cold soluble fraction (XCS). Thus it is inparticular appreciated that the heterophasic propylene copolymer (HECO)fulfils the equationMFR(HECO)/XCS(HECO)>4,preferablyMFR(HECO)/XCS(HECO)>5,more preferablyMFR(HECO)/XCS(HECO)>6wherein“MFR (HECO)” is the MFR₂ (230° C.) [g/10 min] of the heterophasicpropylene copolymer (HECO) measured according to ISO 1133, and“XCS (HECO)” is the amount of the xylene cold soluble (XCS) fraction[wt.-%] of the heterophasic propylene copolymer (HECO) measuredaccording to ISO 6427 (23° C.).

As stated above the heterophasic propylene copolymer (HECO) preferablycomprises

-   -   (a) a polypropylene matrix (M-PP) and    -   (b) an elastomeric copolymer (E1) comprising units derived from        -   propylene and        -   ethylene and/or C4 to C20 α-olefin.

Further the heterophasic propylene copolymer (HECO) preferably comprisesas polymer components only the polypropylene matrix (M-PP) and theelastomeric copolymer (E1). In other words the heterophasic propylenecopolymer (HECO) may contain further additives but no other polymer inan amount exceeding 5 wt-%, more preferably exceeding 3 wt.-%, likeexceeding 1 wt.-%, based on the total heterophasic propylene copolymer(HECO), more preferably based on the polymers present in theheterophasic propylene copolymer (HECO). One additional polymer whichmay be present in such low amounts is a polyethylene which is a reactionproduct obtained by the preparation of the heterophasic propylenecopolymer (HECO). Accordingly it is in particular appreciated that aheterophasic propylene copolymer (HECO) as defined in the instantinvention contains only a polypropylene matrix (M-PP), an elastomericcopolymer (E1) and optionally a polyethylene in amounts as mentioned inthis paragraph. Further, throughout the present invention the xylenecold insoluble (XCI) fraction of the heterophasic propylene copolymer(HECO) represents the polypropylene matrix (M-PP) and optionally—ifpresent—the polyethylene of the heterophasic propylene copolymer (HECO)whereas the xylene cold soluble (XCS) fraction represents theelastomeric part of the heterophasic polypropylene (H-PP1), i.e. theelastomeric copolymer (E1).

Accordingly, as stated above, the elastomeric copolymer (E1) content,i.e. the xylene cold soluble (XCS) content, in the heterophasicpropylene copolymer (HECO) is not more than 45 wt.-%, more preferablynot more than 40 wt.-%, yet more preferably not more than 30 wt.-%,still yet more preferably not more than 25 wt.-%. Thus it is appreciatedthat the elastomeric copolymer (E1) content, i.e. the xylene coldsoluble (XCS) content, in the heterophasic propylene copolymer (HECO) ispreferably in the range of 5 to 45 wt.-%, more preferably in the rangeof 7 to 40 wt.-%, still more preferably in the range of 7 to 35 wt.-%,yet more preferably in the range of 9 to 30 wt.-%, like 10 to 25 wt.-%.

On the other hand the polypropylene matrix (M-PP) content, i.e. thexylene cold insoluble (XCI) content, in the heterophasic propylenecopolymer (HECO) is preferably at least 55 wt.-%, more preferably atleast 60 wt.-%, yet more preferably at least 70 wt.-%, still yet morepreferably at least 75 wt.-%. Thus it is appreciated that thepolypropylene matrix (M-PP) content, i.e. the xylene cold insoluble(XCI) content, is preferably in the range of 55 to 95 wt.-%, morepreferably in the range of 60 to 93 wt.-%, yet more preferably in therange of 65 to 93 wt.-%, still more preferably in the range of 70 to 91wt.-%, like 75 to 90 wt.-%. In case polyethylene is present in theheterophasic propylene copolymer (HECO), the values for thepolypropylene matrix (M-PP) content but not for the xylene coldinsoluble (XCI) content may be a bit decreased.

As explained above a heterophasic propylene copolymer (HECO) comprises apolypropylene matrix (M-PP) in which the elastomeric copolymer (E1) isdispersed.

As will be explained in detail below the polypropylene matrix (M-PP),the propylene homopolymer (H-PP1), and the propylene copolymer (C-PP1)can be unimodal or multimodal, like bimodal in view of the molecularweight distribution and/or the comonomer content distribution.

Thus expression “multimodal” or “bimodal” used herein refers to themodality of the polymer, i.e.

-   -   the form of its molecular weight distribution curve, which is        the graph of the molecular weight fraction as a function of its        molecular weight,        and/or    -   the form of its comonomer content distribution curve, which is        the graph of the comonomer content as a function of the        molecular weight of the polymer fractions.

As will be explained below, the polypropylene matrix (M-PP), thepropylene homopolymer (H-PP1), and the propylene copolymer (C-PP1), ifthey are of multimodal or bimodal character, can be produced by blendingdifferent polymer types, i.e. of different molecular weight and/orcomonomer content. However in such a case it is preferred that thepolymer components of the polypropylene matrix (M-PP), the propylenehomopolymer (H-PP1), and the propylene copolymer (C-PP1) are produced ina sequential step process, using reactors in serial configuration andoperating at different reaction conditions. As a consequence, eachfraction prepared in a specific reactor will have its own molecularweight distribution and/or comonomer content distribution.

When the distribution curves (molecular weight or comonomer content)from these fractions are superimposed to obtain the molecular weightdistribution curve or the comonomer content distribution curve of thefinal polymer, these curves may show two or more maxima or at least bedistinctly broadened when compared with curves for the individualfractions. Such a polymer, produced in two or more serial steps, iscalled bimodal or multimodal, depending on the number of steps.

The polypropylene matrix (M-PP) can be a propylene homopolymer (H-PP2)or a propylene copolymer (C-PP2).

However it is preferred that the propylene matrix (M-PP) is a propylenehomopolymer (H-PP2).

The expression propylene homopolymer as used throughout the instantinvention relates to a polypropylene that consists substantially, i.e.of more than 99.5 wt.-%, still more preferably of at least 99.7 wt.-%,like of at least 99.8 wt.-%, of propylene units. In a preferredembodiment only propylene units in the propylene homopolymer aredetectable. The comonomer content can be determined with FT infraredspectroscopy, as described below in the examples.

Where the polypropylene matrix (M-PP) is a propylene copolymer (C-PP2),more precisely a random propylene copolymer (rC-PP2), the propylenecopolymer (C-PP2), i.e. the random propylene copolymer (rC-PP2),comprises in addition to the units derived from propylene units derivedfrom at least one comonomer selected from the group consisting ofethylene and C₄ to C₂₀ α-olefin, preferably at least one comonomerselected from the group consisting of ethylene and C₄ to C₁₀ α-olefin,e.g. 1-butene or 1-hexene. Most preferably the propylene copolymer(C-PP2), more precisely the random propylene copolymer (rC-PP2), is apropylene ethylene copolymer. The comonomer content, like ethylenecontent, in the propylene copolymer (C-PP2), more precisely in therandom propylene copolymer (rC-PP2), is in such a case preferablyrelatively low, i.e. up to 5.0 wt.-%, more preferably 0.5 to 5.0 wt.-%,still more preferably 1.0 to 4.5 wt.-%, yet more preferably 2.0 to 4.0wt.-%.

Particularly the ethylene is the only comonomer in the propylenecopolymer (C-PP2), more precisely in the random propylene copolymer(rC-PP2).

In case the polypropylene matrix (M-PP) is a propylene homopolymer(H-PP2), the propylene homopolymer (H-PP2) may be multimodal or bimodalin view of the molecular weight. In turn in case the polypropylenematrix (M-PP) is a propylene copolymer (C-PP2), more precisely a randompropylene copolymer (rC-PP2), said propylene copolymer (C-PP2), moreprecisely a random propylene copolymer (rC-PP2), may be multimodal, likebimodal, in view of the comonomer content and/or molecular weight. It isin particular appreciated that the propylene copolymer (C-PP2), moreprecisely the random propylene copolymer (rC-PP2), is multimodal, likebimodal, in view of the comonomer content.

Further in case the polypropylene matrix (M-PP) is of multimodal, likebimodal, character, in particular multimodal, like bimodal, in view ofthe comonomer content, it is appreciated that the individual fractionsare present in amounts influencing the properties of the material.Accordingly it is appreciated that each of these fractions is at leastpresent in the amount of 10 wt.-% based on the polypropylene matrix(M-PP). Accordingly in case of a bimodal system, in particular in viewof the comonomer content, the split of the two fractions is roughly50:50. Thus in one embodiment the polypropylene matrix (M-PP) comprisestwo fractions which differ in their comonomer content, like ethylenecontent, wherein the first fraction is present from 40 to 60 wt.-% andthe second fraction from 60 to 40 wt.-%.

The difference of the comonomer content between the two fractions isdefined in a way of a preferred embodiment in the following paragraph.

In cases where the polypropylene matrix (M-PP) is a propylene copolymer(C-PP2), more precisely a random propylene copolymer (rC-PP2), saidpropylene copolymer (C-PP2), more precisely the random propylenecopolymer (rC-PP2), comprises at least two fractions that have differentcomonomer contents. Preferably the propylene copolymer (C-PP2), moreprecisely the random propylene copolymer (rC-PP2), comprises at leasttwo fractions, more preferably consists of two fractions, that have acomonomer content, like ethylene content, which differs of at least 0.8wt.-%, more preferably differs of at least 1.2 wt.-%. On the other handthe difference in the comonomer content in the two fractions should benot too high, i.e. not higher than 6.0 wt.-%, preferably not higher than5.0 wt %, to avoid any separation tendencies. Thus it is appreciatedthat the propylene copolymer (C-PP2), more precisely the randompropylene copolymer (rC-PP2), comprises at least two fractions, morepreferably consists of two fractions, that have comonomer contents whichdiffer of 2.0 to 6.0 wt.-%, more preferably of 2.5 to 5.0 wt.-%.Accordingly in one embodiment the propylene copolymer (C-PP2), moreprecisely the random propylene copolymer (rC-PP2), comprises, preferablyconsists of, a first fraction being a propylene homopolymer and a secondfraction being a propylene copolymer having a comonomer content,preferably ethylene content, of at least 0.5 wt.-%, more preferably ofat least 1.5 wt.-%, like of at least 2.0 wt.-%, e.g. of at least 2.5wt.-%.

The polypropylene matrix (M-PP) may be produced in a polymerizationstage effected in one or more polymerization reactors. Desirably thepolypropylene matrix (M-PP) comprising two or more different propylenepolymers may be produced by carrying out polymerization in two or moredifferent polymerisation reactors (e.g. bulk and/or gas phase reactors;as bulk reactors, loop reactors are preferred) whereby to generatepolymers of the different desired molecular weight distributions ormonomer make ups in the different polymerization reactors.

Preferably the polypropylene matrix (M-PP) is isotactic. Accordingly itis appreciated that the polypropylene matrix (M-PP) has a rather highpentad concentration, i.e. higher than 90 mol-%, more preferably higherthan 92 mol-%, still more preferably higher than 93 mol-% and yet morepreferably higher than 95 mol-%, like higher than 99 mol-%.

Further and preferably the polypropylene matrix (M-PP) has a rather highmelt flow rate. Accordingly, it is preferred that in the presentinvention the polypropylene matrix (M-PP), i.e. the xylene coldinsoluble (XCI) fraction of the heterophasic propylene copolymer (HECO),has a melt flow rate MFR₂ (230° C.) in a range of 80.0 to 500.0 g/10min, more preferably of 100.0 to 400.0 g/10 min, still more preferablyof 120.0 to 300.0 g/10 min.

Additionally it is desired that the polypropylene matrix (M-PP) has notonly a rather high melt flow rate MFR₂ (230° C.) but also a rather lowxylene cold soluble fraction (XCS). Thus it is preferred that thepolypropylene matrix (M) fulfils the equationMFR/XCS>30,preferablyMFR/XCS>40,more preferablyMFR/XCS>50wherein“MFR” is the MFR₂ (230° C.) [g/10 min] of the polypropylene matrix(M-PP) measured according to ISO 1133, and“XCS” is the amount of the xylene cold soluble (XCS) fraction [wt.-%] ofthe polypropylene matrix (M-PP) measured according to ISO 6427 (23° C.).

Preferably the xylene cold soluble fraction (XCS) of the polypropylenematrix (M-PP) measured according to ISO 6427 (23° C.) is at least 1.0wt.-%. Even more preferred the polypropylene matrix (M-PP) has a xylenecold soluble fraction (XCS) of not more than 3.5 wt.-%, preferably ofnot more than 3.0 wt.-%, like not more than 2.6 wt.-%. Thus a preferredrange is 1.0 to 3.5 wt.-%, more preferred 1.0 to 3.0 wt.-%, still morepreferred 1.2 to 2.6 wt.-%.

Preferably the propylene content in the heterophasic propylene copolymer(HECO) is 75 to 95 wt.-%, more preferably 80 to 94 wt.-%, based on thetotal heterophasic propylene copolymer (HECO), more preferably based onamount of the polymer components of the heterophasic propylene copolymer(HECO), yet more preferably based on the amount of the polypropylenematrix (M-PP) and the elastomeric copolymer (E1) together. The remainingpart constitutes the comonomers, preferably ethylene. Accordingly in apreferred embodiment the comonomer content, i.e. the C2 to C10 α-olefincontent other than propylene, is 5 to 25 wt.-%, more preferably 6 to 20wt.-%.

The second component of the heterophasic propylene copolymer (HECO) isthe elastomeric copolymer (E1).

The elastomeric copolymer (E1) comprises, preferably consists of, unitsderivable from (i) propylene and (ii) ethylene and/or at least anotherC4 to C20 α-olefin, like C4 to C10 α-olefin, more preferably unitsderivable from (i) propylene and (ii) ethylene and at least anotherα-olefin selected form the group consisting of 1-butene, 1-pentene,1-hexene, 1-heptene and 1-octene. The elastomeric copolymer (E1) mayadditionally contain units derived from a non-conjugated diene, howeverit is preferred that the elastomeric copolymer (E1) consists of unitsderivable from (i) propylene and (ii) ethylene and/or C4 to C20α-olefins only. Suitable non-conjugated dienes, if used, includestraight-chain and branched-chain acyclic dienes, such as 1,4-hexadiene,1,5-hexadiene, 1,6-octadiene, 5-methyl-1,4-hexadiene,3,7-dimethyl-1,6-octadiene, 3,7-dimethyl-1,7-octadiene, and the mixedisomers of dihydromyrcene and dihydro-ocimene, and single ring alicyclicdienes such as 1,4-cyclohexadiene, 1,5-cyclooctadiene,1,5-cyclododecadiene, 4-vinyl cyclohexene, 1-allyl-4-isopropylidenecyclohexane, 3-allyl cyclopentene, 4-cyclohexene and1-isopropenyl-4-(4-butenyl) cyclohexane. Multi-ring alicyclic fused andbridged ring dienes are also suitable including tetrahydroindene,methyltetrahydroindene, dicyclopentadiene, bicyclo(2,2,1)hepta-2,5-diene, 2-methyl bicycloheptadiene, and alkenyl, alkylidene,cycloalkenyl and cycloalkylidene norbornenes, such as5-methylene-2-norbornene, 5-isopropylidene norbornene,5-(4-cyclopentenyl)-2-norbornene; and 5-cyclohexylidene-2-norbornene.Preferred non-conjugated dienes are 5-ethylidene-2-norbornene,1,4-hexadiene and dicyclopentadiene.

Accordingly the elastomeric copolymer (E1) comprises at least unitsderivable from propylene and ethylene and may comprise other unitsderivable from a further α-olefin as defined in the previous paragraph.However it is in particular preferred that elastomeric copolymer (E1)comprises units only derivable from propylene and ethylene andoptionally a non-conjugated diene as defined in the previous paragraph,like 1,4-hexadiene. Thus an ethylene propylene non-conjugated dienemonomer polymer (EPDM1) and/or an ethylene propylene rubber (EPR1) aselastomeric copolymer (E1) is especially preferred, the latter mostpreferred.

Like the polypropylene matrix (M-PP) the elastomeric copolymer (E1) canbe unimodal or multimodal, like bimodal. Concerning the definition ofunimodal and multimodal, like bimodal, it is referred to the definitionabove.

In the present invention the content of units derivable from propylenein the elastomeric copolymer (E1) equates with the content of propylenedetectable in the xylene cold soluble (XCS) fraction. Accordingly thepropylene detectable in the xylene cold soluble (XCS) fraction rangesfrom 50.0 to 75.0 wt.-%, more preferably 55.0 to 70.0 wt.-%. Thus in aspecific embodiment the elastomeric copolymer (E1), i.e. the xylene coldsoluble (XCS) fraction, comprises from 25.0 to 50.0 wt.-%, morepreferably 30.0 to 45.0 wt.-%, units derivable from ethylene. Preferablythe elastomeric copolymer (E1) is an ethylene propylene non-conjugateddiene monomer polymer (EPDM1) or an ethylene propylene rubber (EPR1),the latter especially preferred, with a propylene and/or ethylenecontent as defined in this paragraph.

A further preferred requirement of the present invention is that theintrinsic viscosity (IV) of the xylene cold soluble (XCS) fraction ofthe heterophasic propylene copolymer (HECO) is rather low. Rather highvalues of intrinsic viscosity improve the ductility of the heterophasicsystem. Accordingly it is appreciated that the intrinsic viscosity ofthe xylene cold soluble (XCS) fraction of the heterophasic propylenecopolymer (HECO) is below 3.0 dl/g, more preferably below 2.8 dl/g, yetmore preferably below 2.5 dl/g. Even more preferred the intrinsicviscosity of the xylene cold soluble (XCS) fraction of the heterophasicpropylene copolymer (HECO) is in the range of 1.5 to 3.0 dl/g, morepreferably in the range 1.7 to 2.8 dl/g, still more preferably 1.8 to2.6 dl/g. The intrinsic viscosity is measured according to ISO 1628 indecaline at 135° C.

Additionally it is appreciated that the melt flow rate MFR₂ (230° C.)[measured according to ISO 1133] of the heterophasic propylene copolymerand/or of the polypropylene matrix (M-PP) is lower than the melt flowrate MFR₂ (230° C.) [measured according to ISO 1133] of the propylenehomopolymer (H-PP1) and of the propylene copolymer (C-PP1).

Accordingly it is in particular appreciated that the ratio of the meltflow rate MFR₂ (230° C.) of the heterophasic propylene copolymer (HECO)to the melt flow rate MFR₂ (230° C.) of the propylene homopolymer(H-PP1) and the propylene copolymer (C-PP1) [(MFR (HECO)/MFR (H-PP1)) or[(MFR (HECO)/MFR (C-PP 1))] is in the range of 1:4 to 1:50, morepreferably in the range of 1:6 to 1:40). But not only the melt flow rateMFR₂ (230° C.) of the heterophasic system as such shall differ from themelt flow rate MFR₂ (230° C.) of the propylene homopolymer (H-PP1) andthe propylene copolymer (C-PP1), respectively, but preferably also themelt flow rate MFR₂ (230° C.) of the matrix part of the respectiveheterophasic system shall differ from the melt flow rate MFR₂ (230° C.)of the propylene homopolymer (H-PP1) and the propylene copolymer(C-PP1), respectively. As stated above, the heterophasic propylenecopolymer (HECO) is featured by a xylene cold soluble (XCS) fraction anda xylene cold insoluble (XCI) fraction. In the present application thexylene cold insoluble (XCI) fraction of the heterophasic propylenecopolymer (HECO) is essentially identical with the matrix of saidheterophasic propylene copolymer (HECO). Accordingly when talking aboutthe melt flow rate of the polypropylene matrix (M-PP) of heterophasicpropylene copolymer (HECO) the melt flow rate of the xylene coldinsoluble (XCI) fraction of said heterophasic propylene copolymer (HECO)is meant. Accordingly the melt flow rate MFR₂ (230° C.) measuredaccording to ISO 1133 of the xylene cold insoluble (XCI) fraction of theheterophasic propylene copolymer (HECO) is lower, preferably at least250 g/10 min lower, more preferably at least 300 g/10 min lower, yetmore preferably at least 400 g/10 min lower, compared to the melt flowrate MFR₂ (230° C.) measured according to ISO 1133 of the propylenehomopolymer (H-PP1) and of the propylene copolymer (C-PP1),respectively.

Keeping the above in mind it is appreciated that the propylenehomopolymer (H-PP1) and the propylene copolymer (C-PP1) have a melt flowrate MFR₂ (230° C.) measured according to ISO 1133 of at least 500 g/10min, more preferably of at least 600 g/10 min, yet more preferably of atleast 700 g/10 min. Thus the propylene homopolymer (H-PP1) and thepropylene copolymer (C-PP1), respectively, has preferably a melt flowrate MFR₂ (230° C.) measured according to ISO 1133 in the range of 500to 2,000 g/10 min, more preferably in the range of 600 to 1,500 g/10min, like 700 to 1,300 g/10 min.

One possibility to obtain a propylene homopolymer (H-PP1) and apropylene copolymer (C-PP1), respectively, with such high melt flow rateis visbreaking. Thus it is preferred that the propylene homopolymer(H-PP1) and the propylene copolymer (C-PP1), respectively, beforevisbreaking has a melt flow rate MFR₂ (230° C.) of not more than 150g/10 min, more preferably in the range of 20 to 120 g/10 min, yet morepreferably in the range of 30 to 100 g/10 min. Preferably the initiallyused propylene homopolymer (H-PP1) or propylene copolymer (C-PP1) ischosen in such a manner that the visbreaking ratio [final MFR₂ (230°C.)/initial MFR₂ (230° C.)] is 1.3 to 10.0, more preferably 2.0 to 6.5,wherein “initial MFR₂ (230° C.)” is the melt flow rate MFR₂ (230° C.) ofthe propylene homopolymer (H-PP1) or of the propylene copolymer (C-PP1)before visbreaking and “final MFR₂ (230° C.)” is the melt flow rate MFR₂(230° C.) of the propylene homopolymer (H-PP1) or of the propylenecopolymer (C-PP1) after visbreaking. Of course the propylenehomopolymers (H-PP1) and the propylene copolymers (C-PP1) as defined inthe instant invention are also obtainable by polymerisation as such,i.e. without visbreaking. Typically in such polymerization processesZiegler-Natta Catalysts and/or single site catalysts can be employed. Incase the propylene homopolymer (H-PP1) and the propylene copolymer(C-PP1) shall additionally featured by a narrow molecular weightdistribution, the visbroken or single site catalyst producedhomopolymers (H-PP1) and propylene copolymers (C-PP1) are used.

As stated above in case the propylene homopolymer (H-PP1) and thepropylene copolymer (C-PP1) are visbroken, they are further featured bya rather narrow molecular weight distribution. Visbreaking of polymersnot only increases the melt flow rate but additionally narrows themolecular weight distribution. A similarly narrow molecular weightdistribution is also achieved in polymerization with single sitecatalysts. Accordingly it is appreciated that the molecular weightdistribution (M_(w)/M_(n)) of the propylene homopolymer (H-PP1) and ofthe propylene copolymer (C-PP1) is in the range of 2.0 to 6.0, morepreferably in the range of 3.0 to 5.0.

The propylene homopolymer (H-PP1) is preferably an isotactic propylenehomopolymer. Accordingly it is appreciated that the polypropylene matrix(H-PP1) has a rather high pentad concentration, i.e. higher than 90mol-%, more preferably higher than 92 mol-%, still more preferablyhigher than 93 mol-% and yet more preferably higher than 95 mol-%, likehigher than 99 mol-%.

Preferably the propylene homopolymer (H-PP1) has a melting temperatureTm measured according to ISO 11357-3 of at least 145° C., morepreferably of at least 150° C.

Further the propylene homopolymer (H-PP1) has a rather low xylene coldsoluble (XCS) content, i.e. below 4.5 wt.-%, more preferably below 4.0wt.-%, yet more preferably below 3.7 wt.-%. Thus it is appreciated thatthe xylene cold soluble (XCS) content is in the range of 0.5 to 4.5wt.-%, more preferably in the range of 1.0 to 4.0 wt.-%, yet morepreferably in the range of 1.5 to 3.7 wt.-%, like 2.0 to 3.5 wt.-%.

The propylene copolymer (C-PP1) preferably comprises, preferably consistof, units derived from

-   -   (i) propylene and    -   (ii) ethylene and/or at least one C₄ to C₂₀ α-olefin, preferably        at least one α-olefin selected from the group consisting of        ethylene, 1-butene, 1-pentene, 1-hexene and 1-octene, more        preferably ethylene and/or 1-butene, yet more preferably        ethylene.

Accordingly the propylene copolymer (C-PP1) may comprise units derivedfrom propylene, ethylene and optionally at least another C₄ to C₁₀α-olefin. In one specific aspect of the present invention the propylenecopolymer (C-PP1) comprises units derived from propylene, ethylene andoptionally at least another α-olefin selected from the group consistingof C₄ α-olefin, C₅ α-olefin, C₆ α-olefin, C₇ α-olefin, C₈ α-olefin, C₉α-olefin and C₁₀ α-olefin. More preferably the propylene copolymer(C-PP1) comprises units derived from propylene, ethylene and optionallyat least another α-olefin selected from the group consisting of1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene and1-decene, wherein 1-butene and 1-hexene are preferred. It is inparticular preferred that the propylene copolymer (C-PP1) consists ofunits derived from propylene and ethylene. Preferably the unitsderivable from propylene constitutes the main part of the propylenecopolymer (C-PP1), i.e. at least 95.0 wt.-%, preferably of at least 97.0wt.-%, more preferably of at least 98.0 wt.-%, still more preferably of95.0 to 99.5 wt.-%, yet more preferably of 97.0 to 99.5 wt.-%, stillmore preferably of 98.0 to 99.2 wt.-%. The amount of units derived fromC₂ to C₂₀ α-olefins other than propylene in the propylene copolymer(C-PP1), is in the range of 0.5 to 5.0 wt.-%, more preferably 0.5 to 3.0wt.-%, still more preferably 0.8 to 2.0 wt.-%. It is in particularappreciated that the amount of ethylene in the propylene copolymer(C-PP1), in particular in case the propylene copolymer comprises onlyunits derivable from propylene and ethylene, is in the range of 0.5 to5.0 wt.-%, preferably of 0.8 to 2.0 wt.-%.

Further it is appreciated that the xylene cold soluble (XCS) content ofthe propylene copolymer (C-PP1) is a rather low. Accordingly thepropylene copolymer (C-PP1) has preferably a xylene cold soluble (XCS)fraction measured according to ISO 6427 (23° C.) of not more than 14.0wt-%, more preferably of not more than 13.0 wt.-%, yet more preferablyof not more than 12.0 wt.-%, like not more than 11.5 wt.-%. Thus apreferred range is 1.0 to 14.0 wt.-%, more preferred 1.0 to 13.0 wt.-%,still more preferred 1.2 to 11.0 wt.-%.

Preferably the propylene copolymer (C-PP1) is isotactic. Accordingly itis appreciated that the propylene copolymer has a rather high pentadconcentration, i.e. higher than 95 mol-%, more preferably higher than 97mol-%, still more preferably higher than 98 mol-%.

Further it is appreciated that the units derived from C₂ to C₂₀α-olefins other than propylene within the propylene copolymer (C-PP1)are randomly distributed. The randomness indicates the amount ofisolated comonomer units, i.e. those which have no other comonomer unitsin the neighbourhood, compared to the total amount of comonomers in thepolymer chain. In a preferred embodiment, the randomness of thepropylene copolymer (C-PP1) is at least 30%, more preferably at least50%, even more preferably at least 60%, and still more preferably atleast 65%.

Additionally it is appreciated that the propylene copolymer (C-PP1) hasa melting temperature Tm measured according to ISO 11357-3 of least 140°C., preferably at least 145° C., more preferably at least 150° C.Accordingly the melting temperature ranges preferably from 140 to 164°C., more preferably ranges from 150 to 160° C.

Especially good results are obtainable in case the fiber reinforcedcomposition comprises additionally an elastomer (E2). In such a case itis appreciated that the elastomer (E2) is (chemically) different to theelastomeric copolymer (E1).

The elastomer (E2) according to this invention is preferably apolyethylene, in particular a linear low density polyethylene (LLDPE).Accordingly the elastomer (E2), i.e. the linear low density polyethylene(LLDPE), has a density measured according to ISO 1183-187 in the rangeof 820 to 905 kg/m³, more preferably in the range of 840 to 900 kg/m³,yet more preferably in the range of 850 to 890 kg/m³, like in the rangeof 860 to 885 kg/m³.

Further the elastomer (E2), i.e. the linear low density polyethylene(LLDPE), is featured by a specific melt flow rate, namely by a melt flowrate MFR₂ (190° C.) measured according to ISO 1133 in the range of 0.5to 50.0 g/10 min, more preferably in the range of 1.0 to 35.0 g/10 min.

Preferably the elastomer (E2), i.e. the linear low density polyethylene(LLDPE), is a copolymer containing as a major part units derivable fromethylene. Accordingly it is appreciated that the elastomer (E2), i.e.the linear low density polyethylene (LLDPE), comprises at least 50.0wt.-% units derivable from ethylene, more preferably at least 55.0 wt.-%of units derived from ethylene. Thus it is appreciated that theelastomer (E2), i.e. the linear low density polyethylene (LLDPE),comprises 50.0 to 70.0 wt.-%, more preferably 55.0 to 65 wt.-%, unitsderivable from ethylene. The comonomers present in the elastomer (E2),i.e. the linear low density polyethylene (LLDPE), are C4 to C20α-olefins, like 1-butene, 1-hexene and 1-octene, the latter especiallypreferred. Accordingly in one specific embodiment the elastomer (E2),i.e. the linear low density polyethylene (LLDPE), is anethylene-1-octene polymer or an ethylene-1-hexene polymer, with theamounts given in this paragraph.

A further essential component of the present fiber reinforcedcomposition are the fibers (F). Preferably the fibers (F) are selectedfrom the group consisting of glass fibers, metal fibers, ceramic fibersand graphite fibers. Glass fibers are especially preferred. The glassfibers may be either cut glass fibers or long glass fibers, althoughpreference is given to using cut glass fibers, also known as shortfibers or chopped strands. In general, the glass fibers can have alength of from 1 to 50 mm. The cut or short glass fibers used in thefiber reinforced composition preferably have a length of from 1.0 to10.0 mm, more preferably from 3.0 to 7.0 mm, and/or a diameter of from 8to 20 μm, more preferably from 10 to 15 μm.

As previously mentioned the fiber reinforced composition can alsocomprise a compatibilizer (C).

The compatibilizer (C) preferably comprises a modified (functionalized)polymer and optionally a low molecular weight compound having reactivepolar groups. Modified α-olefin polymers, in particular propylenehomopolymers and copolymers, like copolymers of ethylene and propylenewith each other or with other α-olefins, are most preferred, as they arehighly compatible with the polymers of the fiber reinforced composition.Modified polyethylene can be used as well.

In terms of structure, the modified polymers are preferably selectedfrom graft or block copolymers.

In this context, preference is given to modified polymers containinggroups deriving from polar compounds, in particular selected from thegroup consisting of acid anhydrides, carboxylic acids, carboxylic acidderivatives, primary and secondary amines, hydroxyl compounds, oxazolineand epoxides, and also ionic compounds.

Specific examples of the said polar compounds are unsaturated cyclicanhydrides and their aliphatic diesters, and the diacid derivatives. Inparticular, one can use maleic anhydride and compounds selected from C₁to C₁₀ linear and branched dialkyl maleates, C₁ to C₁₀ linear andbranched dialkyl fumarates, itaconic anhydride, C₁ to C₁₀ linear andbranched itaconic acid dialkyl esters, maleic acid, fumaric acid,itaconic acid and mixtures thereof.

Particular preference is given to using a propylene polymer grafted withmaleic anhydride as the modified polymer, i.e. the compatibilizer (C).

The modified polymer, i.e. the compatibilizer (C), can be produced in asimple manner by reactive extrusion of the polymer, for example withmaleic anhydride in the presence of free radical generators (likeorganic peroxides), as disclosed for instance in EP 0 572 028.

Preferred amounts of groups deriving from polar compounds in themodified polymer, i.e. the compatibilizer (C), are from 0.5 to 3% byweight.

Preferred values of the melt flow rate MFR₂ (230° C.) for the modifiedpolymer, i.e. for the compatibilizer (C), are from 1.0 to 500 g/10 min.

The instant composition may additional contain typical other additivesuseful for instance in the automobile sector, like carbon black, otherpigments, antioxidants, UV stabilizers, nucleating agents, antistaticagents and slip agents, in amounts usual in the art.

All components used for the preparation of the instant fiber reinforcedcomposition are known. Accordingly also their preparation is well known.For instance the heterophasic polypropylene (HECO) according to thisinvention is preferably produced in a multistage process known in theart, wherein the polypropylene matrix (M-PP) is produced at least in oneslurry reactor and subsequently the elastomeric copolymer (E1) isproduced at least in one gas phase reactor.

Thus, the polymerization system can comprise one or more conventionalstirred slurry reactors and/or one or more gas phase reactors.Preferably the reactors used are selected from the group of loop and gasphase reactors and, in particular, the process employs at least one loopreactor and at least one gas phase reactor. It is also possible to useseveral reactors of each type, e.g. one loop and two or three gas phasereactors, or two loops and one or two gas phase reactors, in series.

Preferably the process comprises also a prepolymerization with thechosen catalyst system, as described in detail below, comprising theZiegler-Natta procatalyst, the external donor and the cocatalyst.

In a preferred embodiment, the prepolymerisation is conducted as bulkslurry polymerisation in liquid propylene, i.e. the liquid phase mainlycomprises propylene, with minor amount of other reactants and optionallyinert components dissolved therein.

The prepolymerisation reaction is typically conducted at a temperatureof 0 to 50° C., preferably from 10 to 45° C., and more preferably from15 to 40° C.

The pressure in the prepolymerisation reactor is not critical but mustbe sufficiently high to maintain the reaction mixture in liquid phase.Thus, the pressure may be from 20 to 100 bar, for example 30 to 70 bar.

The catalyst components are preferably all introduced to theprepolymerisation step. However, where the solid catalyst component (i)and the cocatalyst (ii) can be fed separately it is possible that only apart of the cocatalyst is introduced into the prepolymerisation stageand the remaining part into subsequent polymerisation stages. Also insuch cases it is necessary to introduce so much cocatalyst into theprepolymerisation stage that a sufficient polymerisation reaction isobtained therein.

It is possible to add other components also to the prepolymerisationstage. Thus, hydrogen may be added into the prepolymerisation stage tocontrol the molecular weight of the prepolymer as is known in the art.Further, antistatic additive may be used to prevent the particles fromadhering to each other or to the walls of the reactor.

The precise control of the prepolymerization conditions and reactionparameters is within the skill of the art.

A slurry reactor designates any reactor, such as a continuous or simplebatch stirred tank reactor or loop reactor, operating in bulk or slurryand in which the polymer forms in particulate form. “Bulk” means apolymerization in reaction medium that comprises at least 60 wt.-%monomer. According to a preferred embodiment the slurry reactorcomprises a bulk loop reactor.

“Gas phase reactor” means any mechanically mixed or fluid bed reactor.Preferably the gas phase reactor comprises a mechanically agitated fluidbed reactor with gas velocities of at least 0.2 m/sec.

The particularly preferred embodiment for the preparation of theheterophasic polypropylene (HECO) of the invention comprises carryingout the polymerization in a process comprising either a combination ofone loop and one or two gas phase reactors or a combination of two loopsand one or two gas phase reactors.

A preferred multistage process is a slurry-gas phase process, such asdeveloped by Borealis and known as the Borstar® technology. In thisrespect, reference is made to EP 0 887 379 A1, WO 92/12182, WO2004/000899, WO 2004/111095, WO 99/24478, WO 99/24479 and WO 00/68315.They are incorporated herein by reference.

A further suitable slurry-gas phase process is the Spheripol® process ofBasell.

Preferably the heterophasic polypropylene composition according to thisinvention are produced by using a special Ziegler-Natta procatalyst incombination with a special external donor, as described below in detail,preferably in the Spheripol® or in the Borstar®-PP process.

One preferred multistage process may therefore comprise the steps of:

-   -   producing a polypropylene matrix in the presence of the chosen        catalyst system, as for instance described in detail below,        comprising the special Ziegler-Natta procatalyst (i), an        external donor (iii) and the cocatalyst (ii) in a first slurry        reactor and optionally in a second slurry reactor, both slurry        reactors using the same polymerization conditions,    -   transferring the slurry reactor product into at least one first        gas phase reactor, like one gas phase reactor or a first and a        second gas phase reactor connected in series,    -   producing an elastomeric copolymer in the presence of the        polypropylene matrix and in the presence of the catalyst system        in said at least first gas phase reactor,    -   recovering the polymer product for further processing.

With respect to the above-mentioned preferred slurry-gas phase process,the following general information can be provided with respect to theprocess conditions.

Temperature is preferably from 40 to 110° C., preferably between 50 and100° C., in particular between 60 and 90° C., with a pressure in therange of from 20 to 80 bar, preferably 30 to 60 bar, with the option ofadding hydrogen in order to control the molecular weight in a mannerknown per se.

The reaction product of the slurry polymerization, which preferably iscarried out in a loop reactor, is then transferred to the subsequent gasphase reactor(s), wherein the temperature preferably is within the rangeof from 50 to 130° C., more preferably 60 to 100° C., at a pressure inthe range of from 5 to 50 bar, preferably 8 to 35 bar, again with theoption of adding hydrogen in order to control the molecular weight in amanner known per se.

The average residence time can vary in the reactor zones identifiedabove. In one embodiment, the average residence time in the slurryreactor, for example a loop reactor, is in the range of from 0.5 to 5hours, for example 0.5 to 2 hours, while the average residence time inthe gas phase reactor generally will be from 1 to 8 hours.

If desired, the polymerization may be effected in a known manner undersupercritical conditions in the slurry, preferably loop reactor, and/oras a condensed mode in the gas phase reactor.

According to the invention the heterophasic polypropylene (HECO) ispreferably obtained by a multistage polymerization process, as describedabove, in the presence of a catalyst system comprising as component (i)a Ziegler-Natta procatalyst which contains a transesterification productof a lower alcohol and a phthalic ester.

The procatalyst used according to the invention is prepared by

-   -   a) reacting a spray crystallized or emulsion solidified adduct        of MgCl₂ and a C₁-C₂ alcohol with TiCl₄    -   b) reacting the product of stage a) with a dialkylphthalate of        formula (I)

-   -    wherein R^(1′) and R^(2′) are independently at least a C₅ alkyl        under conditions where a transesterification between said C₁ to        C₂ alcohol and said dialkylphthalate of formula (I) takes place        to form the internal donor    -   c) washing the product of stage b) or    -   d) optionally reacting the product of step c) with additional        TiCl₄.

The procatalyst is produced as defined for example in the patentapplications WO 87/07620, WO 92/19653, WO 92/19658 and EP 0 491 566. Thecontent of these documents is herein included by reference.

First an adduct of MgCl₂ and a C₁-C₂ alcohol of the formula MgCl₂*nROH,wherein R is methyl or ethyl and n is 1 to 6, is formed. Ethanol ispreferably used as alcohol.

The adduct, which is first melted and then spray crystallized oremulsion solidified, is used as catalyst carrier.

In the next step the spray crystallized or emulsion solidified adduct ofthe formula MgCl₂*nROH, wherein R is methyl or ethyl, preferably ethyland n is 1 to 6, is contacting with TiCl₄ to form a titanized carrier,followed by the steps of

-   -   adding to said titanized carrier        -   (i) a dialkylphthalate of formula (I) with R^(1′) and R^(2′)            being independently at least a C₅-alkyl, like at least a            C₈-alkyl,        -   or preferably        -   (ii) a dialkylphthalate of formula (I) with R^(1′) and            R^(2′) being the same and being at least a C₅-alkyl, like at            least a C₈-alkyl,        -   or more preferably        -   (iii) a dialkylphthalate of formula (I) selected from the            group consisting of propylhexylphthalate (PrHP),            dioctylphthalate (DOP), di-iso-decylphthalate (DIDP), and            ditridecylphthalate (DTDP), yet more preferably the            dialkylphthalate of formula (I) is a dioctylphthalate (DOP),            like di-iso-octylphthalate or diethylhexylphthalate, in            particular diethylhexylphthalate,        -   to form a first product,    -   subjecting said first product to suitable transesterification        conditions, i.e. to a temperature above 100° C., preferably        between 100 to 150° C., more preferably between 130 to 150° C.,        such that said methanol or ethanol is transesterified with said        ester groups of said dialkylphthalate of formula (I) to form        preferably at least 80 mol-%, more preferably 90 mol-%, most        preferably 95 mol.-%, of a dialkylphthalate of formula (II)

-   -   with R¹ and R² being methyl or ethyl, preferably ethyl, the        dialkylphthalat of formula (II) being the internal donor and    -   recovering said transesterification product as the procatalyst        composition (component (i)).

The adduct of the formula MgCl₂*nROH, wherein R is methyl or ethyl and nis 1 to 6, is in a preferred embodiment melted and then the melt ispreferably injected by a gas into a cooled solvent or a cooled gas,whereby the adduct is crystallized into a morphologically advantageousform, as for example described in WO 87/07620. This crystallized adductis preferably used as the catalyst carrier and reacted to theprocatalyst useful in the present invention as described in WO 92/19658and WO 92/19653.

As the catalyst residue is removed by extracting, an adduct of thetitanized carrier and the internal donor is obtained, in which the groupderiving from the ester alcohol has changed.

In case sufficient titanium remains on the carrier, it will act as anactive element of the procatalyst.

Otherwise the titanization is repeated after the above treatment inorder to ensure a sufficient titanium concentration and thus activity.

Preferably the procatalyst used according to the invention contains 2.5wt.-% of titanium at the most, preferably 2.2% wt.-% at the most andmore preferably 2.0 wt.-% at the most. Its donor content is preferablybetween 4 to 12 wt.-% and more preferably between 6 and 10 wt.-%.

More preferably the procatalyst used according to the invention has beenproduced by using ethanol as the alcohol and dioctylphthalate (DOP) asdialkylphthalate of formula (I), yielding diethyl phthalate (DEP) as theinternal donor compound.

Still more preferably the catalyst used according to the invention isthe BHC01P catalyst of Borealis (prepared according to WO 92/19653 asdisclosed in WO 99/24479; especially with the use of dioctylphthalate asdialkylphthalate of formula (I) according to WO 92/19658) or thecatalyst Polytrack 8502, commercially available from Grace.

In a further embodiment, the Ziegler-Natta procatalyst can be modifiedby polymerising a vinyl compound in the presence of the catalyst system,comprising the special Ziegler-Natta procatalyst, an external donor anda cocatalyst, which vinyl compound has the formula:CH₂═CH—CHR³R⁴wherein R³ and R⁴ together form a 5- or 6-membered saturated,unsaturated or aromatic ring or independently represent an alkyl groupcomprising 1 to 4 carbon atoms, and the modified catalyst is used forthe preparation of the heterophasic polypropylene composition accordingto this invention. The polymerized vinyl compound can act as anα-nucleating agent. This modification is in particular used for thepreparation of the heterophasic polypropylene (H-PP1).

Concerning the modification of catalyst reference is made to theinternational applications WO 99/24478, WO 99/24479 and particularly WO00/68315, incorporated herein by reference with respect to the reactionconditions concerning the modification of the catalyst as well as withrespect to the polymerization reaction.

For the production of the heterophasic polypropylenes according to theinvention the catalyst system used preferably comprises in addition tothe special Ziegler-Natta procatalyst an organometallic cocatalyst ascomponent (ii).

Accordingly it is preferred to select the cocatalyst from the groupconsisting of trialkylaluminium, like triethylaluminium (TEA), dialkylaluminium chloride and alkyl aluminium sesquichloride.

Component (iii) of the catalysts system used is an external donorrepresented by formula (III)Si(OCH₃)₂R₂ ⁵  (III)wherein R⁵ represents a branched-alkyl group having 3 to 12 carbonatoms, preferably a branched-alkyl group having 3 to 6 carbon atoms, ora cyclo-alkyl having 4 to 12 carbon atoms, preferably a cyclo-alkylhaving 5 to 8 carbon atoms.

It is in particular preferred that R⁵ is selected from the groupconsisting of iso-propyl, iso-butyl, iso-pentyl, tert.-butyl,tert.-amyl, neopentyl, cyclopentyl, cyclohexyl, methylcyclopentyl andcycloheptyl.

More preferably the external donor is either dicyclopentyl dimethoxysilane [Si(OCH₃)₂(cyclo-pentyl)₂] or diisopropyl dimethoxy silane[Si(OCH₃)₂(CH(CH₃)₂)₂].

The additives as stated above are added afterwards to the heterophasicpolypropylenes, which are collected from the final reactor of the seriesof reactors. Preferably, these additives are mixed into the heterophasicpolypropylene (HECO) to or during the extrusion process in a one-stepcompounding process. Alternatively, a master batch may be formulated,wherein the heterophasic polypropylene (HECO) is first mixed with onlysome of the additives.

The propylene homopolymer (H-PP1) and the propylene copolymer (C-PP1),respectively, as defined in the instant invention may be prepared bypolymerizing, in a slurry reactor, for example a loop reactor, propyleneoptionally together with at least another C₂ to C₂₀ α-olefin(comonomers), in the presence of a polymerization catalyst to produce atleast a part of the propylene homopolymer (H-PP1) or of the propylenecopolymer (C-PP1), respectively. In case only a part of the propylenehomopolymer (H-PP1) or of the propylene copolymer (C-PP1) is produced,this part is then subsequently transferred to a gas phase reactor,wherein in the gas phase reactor propylene is reacted in order toproduce a further part in the presence of the reaction product of thefirst step. In the second step other C₂ to C₂₀ α-olefin(s) (comonomers)can be fed as well if needed. This reaction sequence provides a reactorblend of parts (i) and (ii) constituting the propylene homopolymer(H-PP1) or the propylene copolymer (C-PP1). It is of course possible bythe present invention that the first reaction is carried out in a gasphase reactor while the second polymerization reaction is carried out ina slurry reactor, for example a loop reactor. It is furthermore alsopossible to reverse the order of producing parts (i) and (ii), which hasbeen described above in the order of first producing part (i) and thenproducing part (ii). The above-discussed process, comprising at leasttwo polymerization steps, is advantageous in view of the fact that itprovides easily controllable reaction steps enabling the preparation ofa desired reactor blend. The polymerization steps may be adjusted, forexample by appropriately selecting monomer feed, comonomer feed,hydrogen feed, temperature and pressure in order to suitably adjust theproperties of the polymerization products obtained. It is in particularpossible to obtain a multimodality, preferably the bimodality, of thepropylene homopolymer (H-PP1) or of the propylene copolymer (C-PP1),with respect to the comonomer, like ethylene, distribution as well aswith respect to the molecular weights and MFR₂ (230° C.) values duringsaid multistage polymerization procedures. However the propylenehomopolymer (H-PP1) and the propylene copolymer (C-PP1), respectively,can be also produced in one reactor, like a loop reactor, a method whichis preferred.

Such a process (one reactor or more reactors in sequence) can be carriedout using any suitable catalyst for the preparation of the propylenehomopolymer (H-PP1) and the propylene copolymer (C-PP1), respectively.Preferably, the process as discussed above is carried out using aZiegler-Natta catalyst, in particular a high yield Ziegler-Nattacatalyst (so-called fourth and fifth generation type to differentiatefrom low yield, so called second generation Ziegler-Natta catalysts). Asuitable Ziegler-Natta catalyst to be employed in accordance with thepresent invention comprises a catalyst component, a co-catalystcomponent and at least one electron donor (internal and/or externalelectron donor, preferably at least one external donor). Preferably, thecatalyst component is a Ti—Mg-based catalyst component and typically theco-catalyst is an Al-alkyl based compound. Suitable catalysts are inparticular disclosed in U.S. Pat. No. 5,234,879, WO 92/19653, WO92/19658 and WO 99/33843.

Preferred external donors are the known silane-based donors, such asdicyclopentyl dimethoxy silane or cyclohexyl methyldimethoxy silane.

One embodiment of a process for the propylene homopolymer (H-PP1) or thepropylene copolymer (C-PP1), as discussed above, is a loop phase processor a loop-gas phase process, such as developed by Borealis, known asBorstar® technology, described for example in EP 0 887 379 A1 and WO92/12182.

With respect to the above-mentioned preferred loop (slurry) phaseprocess or preferred slurry-gas phase process, the following generalinformation can be provided with respect to the process conditions.

Temperature of from 40 to 110° C., preferably between 60 and 100° C., inparticular between 80 and 90° C., with a pressure in the range of from20 to 80 bar, preferably 30 to 60 bar, with the option of addinghydrogen in order to control the molecular weight. The reaction productof the slurry polymerization, which preferably is carried out in a loopreactor, is then transferred to the subsequent gas phase reactor (incase of a slurry-gas-phase process), wherein the temperature preferablyis within the range of from 50 to 130° C., more preferably 80 to 100°C., at a pressure in the range of from 5 to 50 bar, preferably 15 to 35bar, again with the option of adding hydrogen in order to control themolecular weight.

The residence time can vary in the reactor zones identified above. Inembodiments, the residence time in the slurry reaction, for example theloop reactor, is in the range of from 0.5 to 5 hours, for example 0.5 to2 hours, while the residence time in the gas phase reactor generallywill be from 1 to 8 hours.

The properties of the propylene homopolymer (H-PP1) or the propylenecopolymer (C-PP1), produced with the above-outlined process may beadjusted and controlled with the process conditions as known to theskilled person, for example by one or more of the following processparameters: temperature, hydrogen feed, comonomer feed, propylene feed,catalyst, type and amount of external donor, split between two or morecomponents of a multimodal polymer.

In case the propylene homopolymer (H-PP1) and the propylene copolymer(C-PP 1), respectively, is subjected to a visbreaking step, thevisbreaking may be carried out in any known manner, like by using aperoxide visbreaking agent. Typical visbreaking agents are2,5-dimethyl-2,5-bis(tert.butyl-peroxy)hexane (DHBP) (for instance soldunder the tradenames Luperox 101 and Trigonox 101),2,5-dimethyl-2,5-bis(tert.butyl-peroxy)hexyne-3 (DYBP) (for instancesold under the tradenames Luperox 130 and Trigonox 145),dicumyl-peroxide (DCUP) (for instance sold under the tradenames LuperoxDC and Perkadox BC), di-tert.butyl-peroxide (DTBP) (for instance soldunder the tradenames Trigonox B and Luperox Di),tert.butyl-cumyl-peroxide (BCUP) (for instance sold under the tradenamesTrigonox T and Luperox 801) and bis(tert.butylperoxy-isopropyl)benzene(DIPP) (for instance sold under the tradenames Perkadox 14S and LuperoxDC). Suitable amounts of peroxide to be employed in accordance with thepresent invention are in principle known to the skilled person and caneasily be calculated on the basis of the amount of the propylenehomopolymer (H-PP1) and the propylene copolymer (C-PP1), respectively,to be subjected to visbreaking, the MFR₂ (230° C.) value of thepolypropylene to be subjected to visbreaking and the desired target MFR₂(230° C.) of the product to be obtained. Accordingly, typical amounts ofperoxide visbreaking agent(s) are from 0.005 to 0.5 wt.-%, morepreferably from 0.01 to 0.2 wt.-%, based on the amount of polypropyleneemployed.

Typically, visbreaking in accordance with the present invention iscarried out in an extruder, preferably in a co-rotating twin screwextruder, so that under the suitable conditions an increase of melt flowrate is obtained. During visbreaking, higher molar mass chains of thestarting product are broken statistically more frequently than lowermolar mass molecules, resulting as indicated above in an overalldecrease of the average molecular weight and an increase in melt flowrate.

The elastomer (E2), i.e. the linear low density polyethylene (LLDPE),can be manufactured in a slurry loop reactor using a single sitecatalyst, e.g. metallocene catalyst. Suitable metallocenes and ways ofpreparing them are within the knowledge and skills of a person skilledin the field. Reference is made to EP 0 260 130, WO 97/28170, WO98/46616, WO 98/49208, WO 99/12981, WO 99/19335, EP 0 836 608, WO98/56831, WO 00/34341, EP 0 423101 and EP 0 537 130. Especiallypreferred the elastomer (E2), i.e. the linear low density polyethylene(LLDPE), is made using a hafnium metallocene such as abis(n-butylcyclopentadienyl) hafnium dichloride or abis(n-butylcyclopentadienyl) hafnium dibenzyl. Other potential catalystsare described in WO 97/28170 and WO 00/40620

For slurry reactors, the reaction temperature will generally be in therange 60 to 110° C. (e.g. 85 to 110° C.), the reactor pressure willgenerally be in the range 5 to 80 bar (e.g. 50 to 65 bar), and theresidence time will generally be in the range 0.3 to 5 hours (e.g. 0.5to 2 hours). The diluent used will generally be an aliphatic hydrocarbonhaving a boiling point in the range −70 to +100° C. In such reactors,polymerisation may if desired be effected under supercriticalconditions. Preferably, the polymer is produced in a continuouslyoperating loop reactor where ethylene is polymerised in the presence ofa polymerisation catalyst as stated above and a chain transfer agentsuch as hydrogen. The diluent is typically an inert aliphatichydrocarbon, preferably isobutane or propane. The elastomer (E2) maycontain various standard polymer additives such as antioxidants, UVstabilisers and polymer processing agents.

For mixing the individual components of the instant fiber reinforcedcomposition, a conventional compounding or blending apparatus, e.g. aBanbury mixer, a 2-roll rubber mill, Buss-co-kneader or a twin screwextruder may be used. Preferably, mixing is accomplished in aco-rotating twin screw extruder. The polymer materials recovered fromthe extruder are usually in the form of pellets. These pellets are thenpreferably further processed, e.g. by injection molding to generatearticles and products of the inventive fiber reinforced composition.

The fiber reinforced composition according to this invention can beproduced by adding

-   -   (a) the heterophasic propylene copolymer (HECO),    -   (b) the propylene homopolymer (H-PP1), the propylene copolymer        (C-PP1), or the mixture of the propylene homopolymer (H-PP1) and        the propylene copolymer (C-PP1),    -   (c) the fibers (F)    -   (d) optionally the elastomer (E2), and    -   (e) optionally the compatibilizer (C),        to an extruder and extruding the same obtaining said fiber        reinforced composition.

The fiber reinforced composition according to the invention may bepelletized and compounded using any of the variety of compounding andblending methods well known and commonly used in the resin compoundingart.

The composition of the present fiber reinforced composition ispreferably used for the production of molded articles, preferablyinjection molded articles. Even more preferred is the use for theproduction of parts of washing machines or dishwashers as well asautomotive articles, especially of car interiors and exteriors, likebumpers, side trims, step assists, body panels, spoilers, dashboards,interior trims and the like.

The current invention also provides articles, like injection moldedarticles, comprising the inventive polypropylene composition.Accordingly the present invention is especially directed to parts ofwashing machines or dishwashers as well as to automotive articles,especially to car interiors and exteriors, like bumpers, side trims,step assists, body panels, spoilers, dashboards, interior trims and thelike, comprising the inventive polypropylene composition.

The present invention will now be described in further detail by theexamples provided below.

EXAMPLES 1. Definitions/Measuring Methods

The following definitions of terms and determination methods apply forthe above general description of the invention as well as to the belowexamples unless otherwise defined.

Quantification of Isotacticity in Polypropylene by ¹³C NMR Spectroscopy

The isotacticity is determined by quantitative ¹³C nuclear magneticresonance (NMR) spectroscopy after basic assignment as e.g. in: V.Busico and R. Cipullo, Progress in Polymer Science, 2001, 26, 443-533.Experimental parameters are adjusted to ensure measurement ofquantitative spectra for this specific task as e.g. in: S. Berger and S.Braun, 200 and More NMR Experiments: A Practical Course, 2004,Wiley-VCH, Weinheim. Quantities are calculated using simple correctedratios of the signal integrals of representative sites in a manner knownin the art. The isotacticity is determined at the pentad level i.e. mmmmfraction of the pentad distribution.

Number average molecular weight (M_(n)), weight average molecular weight(M_(w)) and molecular weight distribution (MWD) are determined by sizeexclusion chromatography (SEC) using Waters Alliance GPCV 2000instrument with online viscometer. The oven temperature is 140° C.Trichlorobenzene is used as a solvent (ISO 16014).

Density is measured according to ISO 1183-187. Sample preparation isdone by compression molding in accordance with ISO 1872-2:2007

Melting temperature Tm is measured according to ISO 11357-3

MFR₂ (230° C.) is measured according to ISO 1133 (230° C., 2.16 kgload).

MFR₂ (190° C.) is measured according to ISO 1133 (190° C., 2.16 kgload).

Quantification of Comonomer Content by FTIR Spectroscopy

The comonomer content is determined by quantitative Fourier transforminfrared spectroscopy (FTIR) after basic assignment calibrated viaquantitative ¹³C nuclear magnetic resonance (NMR) spectroscopy in amanner well known in the art. Thin films are pressed to a thickness ofbetween 100-500 μm and spectra recorded in transmission mode.Specifically, the ethylene content of a polypropylene-co-ethylenecopolymer is determined using the baseline corrected peak area of thequantitative bands found at 720-722 and 730-733 cm⁻¹. Quantitativeresults are obtained based upon reference to the film thickness.

Intrinsic viscosity is measured according to DIN ISO 1628/1, October1999 (in Decalin at 135° C.).

Tensile Modulus; Elongation at break; Yield Stress are measuredaccording to ISO 527-2 (cross head speed=50 mm/min; 23° C.) usinginjection molded specimens as described in EN ISO 1873-2 (dog boneshape, 4 mm thickness).

Flexural Modulus: The flexural modulus was determined in 3-point-bendingaccording to ISO 178 on injection molded specimens of 80×10×4 mmprepared in accordance with ISO 294-1:1996.

Charpy impact test: The Charpy (notched) impact strength (Charpy NIS/IS)is measured according to ISO 179 2C/DIN 53453 at 23° C. and −20° C.,using injection molded bar test specimens of 80×20×4 mm³ prepared inaccordance with ISO 294-1:1996.

The xylene cold solubles (XCS, wt.-%): Content of Xylene solubles (XCS)is determined at 23° C. according ISO 6427.

2. Examples Preparation of PP2

Catalyst

A metallocene catalyst as described in example 1 of EP 1741725 A1 wasused for the preparation of the propylene homopolymer PP2.

Polymerisation

The propylene homopolymer PP2 has been produced in a Borstar PP pilotplant as follows: The catalyst was fed together with triethylaluminiumas cocatalyst with a Al/Zr ratio [mol/mol] of 911 into a stirred tankprepolymerization reactor together with propylene and hydrogen in aratio of 0.12 mol/kmol propylene, the reactor being operated at 25° C.with an average residence time of 0.3 hours. The first polymerizationstep was carried out in a loop reactor at a temperature of 65° C. and apressure of 5500 kPa feeding additional propylene at 160 kg/h withhydrogen in a ratio of 0.38 mol/kmol propylene, maintaining an averageresidence time of 0.45 hours. The resulting polymer was transferredwithout special separation from the process gas to the subsequentreactor. A second polymerization step was carried out in a gas phasereactor at a temperature of 85° C. and a pressure of 2400 kPa,respectively feeding further propylene with hydrogen in a ratio of 5.5mol/kmol propylene. After deactivation of the catalyst with steam anddrying of the resulting polymer powder with warm nitrogen, the resultingpolypropylene homopolymer was compounded together with 0.07 wt % CalciumStearate and 0.60% Irganox B225 (antioxidant combination supplied byCiba Specialty Chemicals) in a twin screw extruder at 230 to 250° C.

The resulting propylene homopolymer has an MFR2 (2.16 kg, 230° C.) of1,060 g/10 min, a density of 902 kg/m³, a melting point of 152° C. andan XS content of 1.0 wt.-%. The GPC determination resulted in a weightaverage molecular weight (Mw) of 61 kg/mol, a number average molecularweight (Mn) of 25 kg/mol and a MWD (Mw/Mn) of 2.4.

TABLE 1 The heterophasic polypropylenes (HECO) used HECO 1 HECO 2 MFR[g/10 min] 100.0 12.0 MFR of XCI [g/10 min] 160 35.0 XCS [wt %] 15 29.8C2 total [wt %] 8.0 15.8 C2 in XCS [wt %] 39 45 IV of XCS [dl/g] 1.9 1.9“HECO 1” is the commercial product BJ356MO of Borealis “HECO 2” is thecommercial product EE041AE of Borealis

TABLE 2 Inventive Examples E 1 E 2 E 3 E 4 HECO 1 [wt.-%] 32.9 26.1 31.133.4 PP 1 [wt.-%] — — — — PP 2 [wt.-%] 18.2 25.0 16.0 17.7 C 1 [wt.-%]2.0 2.0 2.0 — C 2 [wt.-%] — — — 2.0 E 1 [wt.-%] 8.0 — — — E 2 [wt.-%]8.0 12.0 8.0 E 3 [wt.-%] — — — Glass Fiber [wt.-%] 38.0 38.0 38.0 38.0Sum additives [wt.-%] 0.9 0.9 0.9 0.9 MFR 230° C./2.16 kg [g/10 min]14.6 35 27 29 Tens. Modulus [MPa] 7798 7788 7171 7618 Tens. Strength[MPa] 100 101 88 96 Elong. Break [%] 3.8 3.5 4.2 3.9 Charpy ISO 179 1eU+23° C. [kJ/m²] 66 68 73 65 1eA +23° C. [kJ/m²] 15.9 15.3 18.6 15.5 1eU−20° C. [kJ/m²] n.d* n.d* n.d* 64 *n.d. not determined

TABLE 3 Inventive Examples E 5 E 6 E 7 E 8 HECO 1 [wt.-%] 31.1 18.6 9.618.6 PP 1 [wt.-%] — — 49.5 40.5 PP 2 [wt.-%] 16.0 40.5 — — C 1 [wt.-%]2.0 2.0 2.0 2.0 C 2 [wt.-%] — — E 1 [wt.-%] — — — — E 2 [wt.-%] — — — —E 3 [wt.-%] 12.0 — — — Glass Fiber [wt.-%] 38.0 38.0 38.0 38.0 Sumadditives [wt.-%] 0.9 2.00.9 0.9 0.9 MFR 230° C./2.16 kg [g/10 min] 2675 23 18 Modulus [MPa] 7094 8600 8891 8941 Tens. Strength [MPa] 85 120125 125 Elong. Break [%] 4.5 2.5 2.3 2.4 Charpy ISO 179 1eU +23° C.[kJ/m²] 76 59 50 53 1eA +23° C. [kJ/m²] 20.2 11.5 12.6 12.7 1eU −20° C.[kJ/m²] 70 n.d* n.d* n.d* *n.d. not determined

TABLE 4 Comparative Examples CE 1 CE 2 CE 3 CE4 HECO 1 [wt.-%] 54.1 25.822.8 0.0 HECO 2 [wt.-%] 0.0 33.3 36.3 0.0 PP 1 [wt.-%] 0.0 0.0 0.0 59.1C 1 [wt.-%] 2.0 2.0 2.0 2.0 E 1 [wt.-%] 5.0 0.0 0.0 0.0 Glass Fiber[wt.-%] 38 38 38 38 Sum additives [wt.-%] 0.9 0.9 0.9 0.9 MFR 230°C./2.16 kg [g/10 min] 7.5 3.4 5.6 31 Tens. Modulus [MPa] 7878 7572 76878702 Tens. Strength [MPa] 96 90 84 126 Elong. Break [%] 3.6 3.8 4.7 1.3Charpy ISO 179 1eU +23° C. [kJ/m²] 62 65 64 49 1eA +23° C. [kJ/m²] 15.720 18.8 12.6 1eU −20° C. [kJ/m²] 62 n.d* n.d* 35 *n.d. not determined

PP1 is the commercial propylene homopolymer product HL512FB of BorealisAG having an MFR₂ (230° C.) of 1,200 g/10 min; an XCS of 2.8 wt.-%, a Tmof 158° C. and an MWD (Mw/Mn) of 2.8

PP2 is an experimental propylene homopolymer prepared according to thedescription below with an MFR₂ (230° C.) of 1,060 g/10 min; an XCS of1.0 wt.-%, a Tm of 152° C. and an MWD (Mw/Mn) of 2.4

C 1 is the commercial maleic anhydride functionalized polypropyleneExxelor PO1020 of Exxon Mobil having a density 0.9 g/cm³, an MFR (230°C./2.16 kg) of 430 g/10 min and an MAH content of 1.0 mol %

C 2 is the commercial maleic anhydride functionalized polypropyleneScona TPPP 2112FA of Kometra GmbH, Germany with a density 0.9 g/cm³having an MFR (230° C./2.16 kg) of 5 g/10 min and an MAH content of 1.2mol %.

E 1 is the commercial ethylene-octene copolymer ENGAGE 8100 of DowElastomers with an MFR₂ (190° C.) of 1.0 g/10 min and a density of 0.87g/cm³

E 2 is the commercial ethylene-octene copolymer Exact 8230 of ExxonMobil with an MFR₂ (190° C.) of 1.0 g/10 min and a density of 0.88g/cm³.

E 3 is the commercial ethylene-octene copolymer ENGAGE 8400 of DowElastomers with an MFR₂ (190° C.) of 30.0 g/10 min and a density of 0.87g/cm³.

Glass Fiber is the commercial product Vetrotex EC13 P968 of Saint-GobainVetrotex International, Germany, which is a short-cut glass fiber with13 μm fibre diameter and 6 mm length being surface coated

Sum additives All compositions listed in tables 2, 3 and 4 contain thesame additive composition: 0.1 wt.-% calcium stearate (Calcium stearateSP, commercially available from Faci, Italy), 0.2 wt.-%Tris(2,4-di-t-butylphenyl)phosphate (Irgafos 168, commercially availablefrom CIBA Specialty Chemicals, Switzerland), 0.2 wt.-%1,3,5-tri-methyl-2,4,6-tris-(3,5-di-tert.butyl-4-hydroxyphenyl)benzene(irganox 1330, commercially available from CIBA Specialty Chemicals,Switzerland) and 0.4 wt.-% Di-octadecyl-disulphide (Hostanox SE10,commercially available from Clariant, Germany).

We claim:
 1. Fiber reinforced composition comprising (a) a heterophasicpropylene copolymer (HECO), (b) a propylene homopolymer (H-PP1) and/or apropylene copolymer (C-PP1), and (c) fibers (F), wherein (i) thepropylene copolymer (C-PP1) comprises not more than 2.0 wt.-% C2 to C10α-olefins other than propylene, (ii) the propylene homopolymer (H-PP1)and the propylene copolymer (C-PP1) have a melt flow rate MFR₂ (230 C)measured according to ISO 1133 of at least 600 g/10 min, and (iii) thecomposition has a melt flow rate MFR₂ (230 C) measured according to ISO1133 of at least 10 g/10 min.
 2. Fiber reinforced composition accordingto claim 1, wherein the heterophasic propylene copolymer (HECO)comprises a polypropylene matrix (M-PP) and dispersed therein anelastomeric copolymer (E1) comprising units derived from propylene andethylene and/or C4 to C20 α-olefin.
 3. Fiber reinforced compositionaccording to claim 2, wherein the polypropylene matrix (M-PP) has alower melt flow rate MFR₂ (230° C.) measured according to ISO 1133 thanthe propylene homopolymer (H-PP1) and the propylene copolymer (C-PP1).4. Fiber reinforced composition according to claim 2, wherein thecomposition comprises additionally (a) an elastomer (E2) being differentto the elastomeric copolymer (E1), and/or (b) a compatibilizer (C). 5.Fiber reinforced composition according to claim 4, wherein thecomposition comprises (a) 5.0 to 50.0 wt.-% of the heterophasicpropylene copolymer (HECO) (b) 10.0 to 60.0 wt.-% of the propylenehomopolymer (H-PP1), of the propylene copolymer (C-PP1), or of themixture of the propylene homopolymer (H-PP1) and the propylene copolymer(C-PP1) (c) 10.0 to 45.0 wt.-% of fibers, (d) optionally 3.0 to 20.0wt.-% of the elastomer (E2), and (e) optionally 0.5 to 4.0 wt.-% of thecompatibilizer (C), based on the total composition.
 6. Fiber reinforcedcomposition according to claim 1, wherein the heterophasic propylenecopolymer (HECO) has (a) a xylene cold soluble content (XCS) measuredaccording ISO 6427 (23 C) of not more than 45 wt.-%, and/or (b) a meltflow rate MFR₂ (230 C) measured according to ISO 1133 of more than 10g/10 min, and/or (c) a total C2 to C10 α-olefin content other thanpropylene of 5 to 25 wt.-%.
 7. Fiber reinforced composition according toclaim 1, wherein the propylene homopolymer (H-PP1) has (a) a melt flowrate MFR₂ (230 C) measured according to ISO 1133 in the range of 600 to1,500 g/10 min and/or (b) a molecular weight distribution (M_(w)/M_(n))of 2.0 to 6.0 and/or (c) melting temperature Tm measured according toISO 11357-3 of at least 145 C.
 8. Fiber reinforced composition accordingto claim 1, wherein the propylene copolymer (C-PP1) has (a) a melt flowrate MFR₂ (230 C) measured according to ISO 1133 in the range of 600 to1,500 g/10 min and/or (b) a molecular weight distribution (M_(w)/M_(n))of 2.0 to 6.0 and/or (c) melting temperature Tm measured according toISO 11357-3 of at least 140 C.
 9. Fiber reinforced composition accordingto claim 1, wherein the fibers are selected from the group consisting ofglass fibers, metal fibers, ceramic fibers and graphite fibers. 10.Fiber reinforced composition according to claim 4, wherein the elastomer(E2) is a linear low density polyethylene (LLDPE).
 11. Fiber reinforcedcomposition according to claim 4, wherein the elastomer (E2) (a)comprises units derived from ethylene and at least one C4 to C20α-olefin, and/or (b) has an ethylene content of at least 50 wt.-%,and/or (c) has a density measured according to ISO 1183-187 in the range820 to 900 kg/m³, and/or (d) has a melt flow rate MFR₂ (190 C) measuredaccording to ISO 1133 in the range of 0.5 to 50.0 g/10 min.
 12. Fiberreinforced composition according to claim 4, wherein the compatibilizer(C) is a maleic anhydride functionalized polypropylene.
 13. Automotivearticle comprising a fiber reinforced composition comprising: (a) aheterophasic propylene copolymer (HECO), (b) a propylene homopolymer(H-PP1) and/or a propylene copolymer (C-PP1), (c) an elastomer (E2), and(d) fibers (F), wherein (i) the propylene copolymer (C-PP1) comprisesnot more than 2.0 wt.-% C2 to C10 α-olefins other than propylene, (ii)the propylene homopolymer (H-PP1) and the propylene copolymer (C-PP1)have a melt flow rate MFR₂ (230° C.) measured according to ISO 1133 ofat least 600 g/10 min, and (iii) the composition has a melt flow rateMFR₂ (230° C.) measured according to ISO 1133 of at least 10 g/10 min.14. Fiber reinforced composition according to claim 1 formed intoautomotive articles.
 15. Process for the preparation of a fiberreinforced composition comprising the steps of adding (a) a heterophasicpropylene copolymer (HECO), (b) a propylene homopolymer (H-PP1), apropylene copolymer (C-PP1), or a mixture of the propylene homopolymer(H-PP1) and the propylene copolymer (C-PP1), (c) a fibers (F) (d)optionally a elastomer (E2), and (e) optionally a compatibilizer (C), toan extruder and extruding the same obtaining said fiber reinforcedcomposition, wherein the propylene homopolymer (H-PP1) and the propylenecopolymer (C-PP1) have a melt flow rate MFR₂ (230° C.) measuredaccording to ISO 1133 of at least 600 g/10 mol.
 16. Fiber reinforcedcomposition according to claim 1, wherein the heterophasic propylenecopolymer (HECO) comprises a propylene homopolymer (H-PP2) and dispersedtherein an elastomeric copolymer (E1) comprising units derived frompropylene and ethylene and/or C4 to C20 α-olefin.